Digital Image Watermarking Algorithm And Its Application Based On Chaotic Map

The rapid development of computer and communication technology and the popularization of Internet provide a great convenient way for saving and spreading multimedia digital product, however, which also reveal the problems of the security protection of information which is becoming more and more serious. The copyright protection of digital product has become the problem which is urgently needed to be solved in information times. As an effective means of digital copyright and data security protection, digital watermarking technology has gained wide attention and rapid development, and has become a hot research topic in the field of international information security. Because of its high sensitivity to initial values, good correlation, low-frequency bandwidth and so on, the information security technology based on Chaos system arouses great interest and enthusiasm in the international academic community. In this paper, the digital watermarking technology based on chaos theory is studied, and the primary contributions of this paper contain the following points:(1)We first make a recapitulative introduce of the digital watermarking technology including its basic concept, character, sort, attack types, related wavelet analysis and Chaos theory and so on, Systematically expounding its basic principles and methods.(2)As chaotic sequence is extremely sensitive to the initial parameters, even small changes in initial value can lead to different random sequences, a digital watermarking algorithm based on the differential energy of the middle frequency sub-bands of the DCT coefficients of the original image is proposed in this paper, which encrypts and permutes meaningful watermark with chaotic map first. Watermark is extracted without original image. Lastly experiment result for this watermarking algorithm is given.(3)Taking advantage of the time-frequency analysis characteristic of wavelet transform and the human visual system(HVS), considering the background that the ROI(region of interest) of medical image is not allowed to be destroyed, a digital watermarking algorithm based on ROI information of medical images and DWT is proposed, which selects the gray meaningful image as the watermark and encrypts by chaos. Watermark is extracted without original image. Lastly experiment result for this watermarking algorithm is given.(4)To improve the security performance of the single chaos-based digital watermarking system, a medical image watermarking algorithm based on the new mixed chaotic system is proposed. Lastly experiment result for this watermarking algorithm is given.